Originally Posted by nextri

The thing is though. It's not skimmed traffic. It's clicked traffic. But the way the system works, for each trade partner, or sold campaign, the system calculates what thumb gets the highest click through ratio, and shows that thumb. So you can maximize the amount of traffic being sent from each spot you use it on.

And since it isn't skimmed traffic, advertisers can pay more for it, because it's higher quality.
But it still attracts a lot of clicks, compared to banner spots or text links. And another benefit is that your not pissing of the surfers, because the surfers get what they expect when clicking a thumb, in most cases.